将信号的值分配给变量

Posted 2023-03-30

【中文标题】将信号的值分配给变量

【英文标题】：Assigning values of a signal to a variable

【发布时间】：2019-04-30 21:40:48

【问题描述】：

我是 python 中的信号和插槽的新手，目前正在使用 Pyqt5 设计一个 GUI。用户需要从混合的 qcombobox 中进行选择，其中每个元素都是一个 qmenu。我正在尝试存储用户使用信号选择的路径。

选择 GUI 的图像

尝试：

在类中使用 pathChanged 为：

pathChanged = QtCore.pyqtSignal(list)

稍后在 init 中打印所选路径：

combo.pathChanged.connect(print)

但这不会将我的路径值保存到变量中，而只是在控制台上显示它。如果我将上述内容等同于一个变量，那么我只会收到内存位置。

如何将选择存储在列表中，并在每次用户选择后附加列表？

尝试从原代码实现思路：https://***.com/a/52723148/6942881

我的代码是：

from PyQt5 import QtCore, QtWidgets


data = 'Concept': 
            "Aircraft":
                    "Blended Wing":[],
                    "Lifting Body":["Flat Bottom","Round Bottom","Wing"],
                    "Wing Body":["Fixed","Rotary","Swept"],
            "Launch Vehicle":
                    "SSTO":["Expendable","Reusable","Partially Reusable"],
                    "TSTO":["Expendable","Reusable","Partially Reusable"],
                    "MSTO":["Expendable","Reusable","Partially Reusable"]
                    
        


class ComboBoxExpandable(QtWidgets.QPushButton):
    currentTextChanged = QtCore.pyqtSignal(str)
    pathChanged = QtCore.pyqtSignal(list)

    def setData(self, value):
        menu = QtWidgets.QMenu(self)
        self.setMenu(menu)
        self.append_element(value, menu)
        menu.triggered.connect(self.on_triggered)
    def printer(self,path):
        # print(path)
        return path

    @QtCore.pyqtSlot(QtWidgets.QAction)
    def on_triggered(self, action):
        self.setText(action.text())
        path = [action.text()] 
        w = action.parentWidget()
        while w.parentWidget() and isinstance(w.parentWidget(), QtWidgets.QMenu):
            path.insert(0, w.title())
            w = w.parentWidget()

        self.pathChanged.emit(path)
        self.currentTextChanged.emit(self.text())
        self.printer(path)


    @staticmethod
    def append_element(value, menu):
        if isinstance(value, list):
            for e in value:
                ComboBoxExpandable.append_element(e, menu)
        elif isinstance(value, dict):
            for k, v in value.items():
                if v==[]:
                    menu.addAction(k)
                else:
                    ComboBoxExpandable.append_element(v, menu.addMenu(k))
        else:
            menu.addAction(value)


class Widget(QtWidgets.QWidget):
    def __init__(self, parent=None):
        super(Widget, self).__init__(parent)

        combo = ComboBoxExpandable()
        combo.setData(data)
        result_label = QtWidgets.QLabel()
        combo.currentTextChanged.connect(result_label.setText)
        combo.pathChanged.connect(print)
        lay = QtWidgets.QFormLayout(self)
        lay.addRow("Select Concept: ", combo)
        lay.addRow("Concept Selected: ", result_label)

if __name__ == '__main__':
    import sys

    app = QtWidgets.QApplication(sys.argv)
    w = Widget()
    w.show()
    sys.exit(app.exec_())

【参考方案1】：

解决方案是创建一个连接到该信号的槽，将通过该信号传输的列表添加到该类的成员中：

class Widget(QtWidgets.QWidget):
    def __init__(self, parent=None):
        super(Widget, self).__init__(parent)

        self._paths = [] # <---container
        combo = ComboBoxExpandable()
        combo.setData(data)
        result_label = QtWidgets.QLabel()
        combo.currentTextChanged.connect(result_label.setText)
        combo.pathChanged.connect(self.on_pathChanged)
        lay = QtWidgets.QFormLayout(self)
        lay.addRow("Select Concept: ", combo)
        lay.addRow("Concept Selected: ", result_label)

    @QtCore.pyqtSlot(list)
    def on_pathChanged(self, path):
        self._paths.append(path) # append path
        print(self._paths)